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arXiv · hep-ph/9510375

In a hot, chirally symmetric phase, $π^0$ doesn't go into $2 γ$, but $π^0 σ$ does

Robert D. Pisarski
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Abstract

In a constituent quark model at nonzero temperature, the amplitude for $π^0 \rightarrow 2 γ$ vanishes in a chirally symmetric phase, while that for $π^0 σ\rightarrow 2 γ$ does not.

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Robert D. Pisarski. 1995-10-23. In a hot, chirally symmetric phase, $π^0$ doesn't go into $2 γ$, but $π^0 σ$ does. https://doi.org/10.1142/9789812830296_0005

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